Among the various sensors in modern vehicles, the oxygen sensor is one of the most essential. It is popularly called the O2 sensor (as oxygen’s chemical formula is O2), and it performs the role of monitoring the amount of unburned oxygen in the exhaust.
The monitoring of oxygen levels is necessary to measure the fuel mixture in your car. The O2 sensor enables your car’s computer to know whether the oxygen level is low (the fuel mix has been burning rich) or there is excessive oxygen (the fuel mix is burning lean). By determining the ratio of fuel to air, the car engine can make the required adjustments to ensure optimal running.
When to Replace the Oxygen Sensor?
The O2 sensor is not the typical maintenance item in your vehicle that requires frequent replacement (such as oil filters). Therefore, it is only replaced when it fails. If you continue to run the vehicle with a bad O2 sensor, it would lead to poor fuel economy, greater emission levels, and it will ultimately damage other components in your vehicle, such as the catalytic converter.
The issue with timely replacement of an oxygen sensor is that cars do not have a warning light that will signal when it is failing. Based on this information, you need to be alert to other key signs to know when your O2 sensor needs replacement. Higher fuel consumption and the engine light illuminating on your dashboard are common signals that should alert you about the condition of the oxygen sensor.
Check Engine Light is Illuminated
The check engine light of your vehicle is your first line of defense. This light will be on if your car’s O2 sensor is bad or failing. The moment this light gets illuminated, you should get in touch with an automotive technician at the first opportunity for a thorough Check Engine Light inspection.
The engine light may come on for a variety of reasons. Therefore, you will need assistance from a professional technician who can accurately identify the problem. Apart from the engine light, you should also keep track of your car’s mileage. If the mileage is getting poorer, chances are that you have a failing O2 sensor that requires replacement.
Foul Smell and Poor Gas Mileage
The fuel delivery as well as fuel combustion mechanisms in your vehicle will be disrupted if the O2 sensor is going bad. The failing oxygen sensor could lead to an incorrect air to fuel ratio, or it may inject excessive fuel in the engine. This will not only reduce your gas mileage, but also create foul, sulfuric smell, and sometimes even produce thick, black smoke in the exhaust.
It is best to maintain a record of how many gallons of gas you are filling up and at what intervals. If you realize that you have been filling up the gas task at an unusually high frequency, get an experienced car mechanic to examine your O2 sensor.
Rough Engine Sound and Irregular Performance
If your engine has been sounding rough lately, or you find you that the car has been running irregularly, the problem could lie with your oxygen sensor. The engine’s efficiency comes down when the fuel and oxygen mixture in your car becomes too rich or too lean.
A bad O2 sensor can disrupt some of the vital functions, such as the air to fuel ratio, engine timing, and combustion intervals. This can make your vehicle’s performance irregular or unpredictable, while the engine sound can become rough.
Failing the Emissions Test
A defective oxygen sensor is the cause behind a large number of emission test failures. If you ignore the replacement of your O2 sensor even when it is long overdue, you could end up with significant damage to some of the car components and failed emissions tests.
It may result in thousands of dollars in repair costs to have your vehicle up and running again in good condition. A bad O2 sensor could even expose the car occupants to carbon monoxide emissions. For these reasons, it makes sense to have your faulty oxygen sensor replaced sooner than later.
An Older Car
As your vehicle becomes aged, the oxygen sensor will gradually become caked with combustion byproducts, such as fuel additives, lead, oil ash, and sulfur. This can keep the sensor from transmitting correct signals to the vehicle’s computer system.
If you have been using low quality gasoline or a fuel that is not recommended for your model, it can contribute to the failure of your oxygen sensor over time.
As a thumb rule, you may consider replacing your oxygen sensors every 65,000 to 90,000 miles, if your vehicle is less than 15 years old. This will reduce pollution and keep your car engine running efficiently. If your car is older than 15 years, it is best to replace the O2 sensors every 50,000 to 65,000 miles.
How to Replace the O2 Sensor?
Replacement oxygen sensors is not really a tough job in most cases. But this will depend on your car model because in some of the models, it can be difficult to access the sensor. The procedure may involve removal of some other parts as well.
Another issue that could arise with oxygen sensor replacement is it goes through a lot of heating and cooling cycles, which can cause the threads to seize. This will make the sensor removal more difficult. Some technicians may choose to heat up the sensor’s base with a torch or heat gun to expand the metal so that the removal becomes easier.
You should remember that oxygen sensor is one of the vital components in your vehicle, and it will need to be replaced when it has lived its life. There is virtually no way to repair or fix a failed sensor, so replacement is the best option. Choose an experienced automotive technician for this task unless you are yourself a pro at car repairs.
Timely replacement of the O2 sensor will extend the life and performance of your vehicle engine, improve the fuel economy, and lower the emissions. It is a win-win situation for you and the environment, so track the signs and talk to an auto repair expert when you believe the oxygen sensor may be failing.